In this feasibility study, investigators from Baylor University in Waco, TX examined whether a hypnotic intervention could reduce hot flashes.
Thirteen postmenopausal women received 5 sessions of guided self-hypnosis in which all hypnotic inductions were recordings.  Additionally, they were given guidance regarding symptom monitoring, individualizing their guided imagery, and on the general practice of self-hypnosis.
Hot flashes were determined through diaries.

Results indicated that the average frequency of hot flashes decreased by 72% (p < .001) and hot-flash scores decreased by 76% (p < .001) on average.

The researchers concluded that guided self-hypnosis reduced perceived hot flashes in the pilot study with postmenopausal women, supporting the possible feasibility and potential benefit of the intervention.

Citation:  Elkins G, Johnson A, Fisher W, Sliwinski J, Keith T.A pilot investigation of guided self-hypnosis in the treatment of hot flashes among postmenopausal women. International Journal of Clinical and Experimental Hypnosis. 2013; 61 (3): pages 342-50.